Elastomeric magnetic objects have heretofore been prepared by combining a pulverized magnetic material with an elastomeric material such as a rubber or synthetic resin in a semi-liquid, fluidity state to form a mixture which is loaded in a kneading machine. The mixture unloaded from the latter is then shaped into a predetermined size and form by extrusion or pressing, followed by vulcanizion to yield a desired object. In such conventional preparation techniques, a satisfactory, uniform mixing of magnetic particles and boding elastomeric material could not be attained. Thus, in the resulting product, magnetic particles distribute rather irregularly in the supporting elastomeric material which also serves to only loosely carry the distributed magnetic particles. The attempt to increase the strength at which the particles are distributorily held has resulted in the requirement for a larger amount of the elastomeric material. Because of this and the lack of uniformity of distribution of magnetic particles in the supporting elastomeric material, magnetic properties attainable heretofore with elastomeric magnetic objects have been undesirably limited.